1. Field of the Invention
The present invention relates to a switching device and a method for preventing malfunction of the same; and, more particularly, to a switching device capable of preventing a shoot through phenomenon which is generated by becoming a plurality of switches to be ON at the same time, wherein the switches must alternatively become ON, and a method for preventing malfunction of the same.
2. Description of the Related Art
The switching device such as an insulated gate bipolar transistor (IGBT) has been widely used in a lot of field such as a new renewable energy generating inverter, a general purpose inverter and an uninterruptible power supply and or the like.
As viewing a malfunction example of the above switching device, at first, there is an arm short phenomenon that one device is broken in one arm, in this case, the breakdown of the device is induced since a rapid current flows into the switch when a signal is applied to the normal switch.
Thereafter, when the same signals are simultaneously generated at two switched in one switch due to the abnormal phenomenon of the controller or the gate driver, a short current is generated, such phenomenon is called a series arm short.
And then, if the load of the IGBT is short or an output line is erroneously connected, the short can be generated at the output side or a ground short phenomenon can be generated.
FIG. 1 is an exemplary view illustrating a case to generate the series arm short as the second type among the malfunctions of the above switching device, such malfunctions are mainly generated at the time when the malfunction is generated at the controller or the power of the controller is reset.
Due to the above malfunctions, when the rapid current flows, the switch is damaged and the failure of products including the switch may be induced.
FIG. 2 is a conceptual view showing a construction of a conventional switching device, referring to FIG. 2, the PWM_A control signal generated at the controller controls the ON•OFF operations of the switch by applying the PWM_B signal to the control unit of the switch through the gate driver. At this time, when the control signal generated at the controller makes the first switch and the second switch to be ON, the failures of the switching device and products including the switching device can be induced.